Recent flood plain:
This region comprises of the vast plain land of Bangladesh. The land is formed by the alluvium carried by different rivers, particularly the Ganges, the Brahmmaputra and the Padma.
Environmental characteristics: The soil of this region is made of alluvium and is very fertile. In the rainy season many aquatic plants, by death and decomposition, converted to organic manure and thus make the soil more fertile.
Plants: Among the aquatic plantsNymphaea noucheli(Shapla) [our national flower], Lotus, Ipomea, Halencha, Shola, Vallisnaria (Pat Shaola) Urticularia,Azolla, Lamna, Wolfia (smallest flowering plant) Eichornea (Kachuripana), Pistea (Topapana), Trapa (Paniphal), Polygonum (Panimarich), and varioustypes of grasses are the major plants. In this region there grows plenty of fresh water algae among which phytoplankton, a primary producer, serve as the food of fish and other aquatic animals.
In uncultivated lands, Kalkesunda (Cassia), Shetodron (Leucas) Raktodron, Dhutura (Datura), Hatishur (Heliotropium), Mikania, Bhat (Clerodendron), Muktajhuri (Acalypha), Kachu (Colocasia), Khagra (Xanthiun) etc. are the major plants. Around the houses betel nut, coconut, mango, jackfruit, banana, litchi, tamarind, plum, jamboline, bamboos, Barun, Pipul, Akondo (Calotropis) etc. are the main plants.
Among the crop plants paddy (Oryza sativa), deep-water rice (a variety of paddy grown in deep water), and jute (Chorchorus sp.) are the main.
Animals: In this region there live different species of small and large animals.Among them, toad, frog, lizard, tortoise, different varieties of snakes, mongoose, sparrow, Shalik, Moyena, parrot, crow, kite, vulture, buffalo, cow, goat, sheep etc. are notable. Besides these, in the rivers of this region there is fresh water dolphin (Shushuk) and different species of fish. In ponds and other water reservoirs there are many species of small and big fishes, aquatic snakes, tortoise etc.